We find that both in the limb-brightened edge of the Veil Shell and in OMC4 at \(d<1\,\mathrm {pc}\)  the FIR intensity scales with \(d^{-2}\)  approximately. The incident radiation field at a distance of \(1\,\mathrm {pc}\)  is \(G_0\sim 500\) , derived from the presumed face-on geometry of the ISF in the OMC4 region using \(G_0\simeq I_{\mathrm {FIR}}/2/1.3\times 10^{-4}\,\mathrm {erg\,s^{-1}\,cm^{-2}\,sr^{-1}}\)  [1]}. This is a third of the value derived from the total FIR luminosity from the Orion Nebula (cf. Paper I) and reflects the geometry of the region. In fact, this discrepancy corresponds to an angle of \(70^{\circ }\)  between the incident radiation and the surface normal. At \(d>1\,\mathrm {pc}\) , the FIR intensity in OMC4 scales with an exponent somewhat smaller than 2. This region is characterized by large columns of cold dust that produce a FIR excess (cf. Paper I).
